Oxide semiconductor alloys of x(LiGaO2)1∕2–(1−x)ZnO were synthesized by a standard solid state reaction. The wurtzite-type single phases were obtained in the wide composition range of x⩽0.38 because the β-LiGaO2 possesses a wurtzite-derived structure and approximately the same lattice constants with ZnO. The resulting alloys showed characteristics of wide band gap oxide n-type semiconductor; the optical transparency reached over to the ultraviolet (UV) light. The electrical conductivity and energy band gap for 0.38(LiGaO2)1∕2–0.62ZnO were 8.2Ω−1cm−1 and 3.7eV, respectively, at room temperature. The alloy is a good candidate for the barrier material of the ZnO-based heterostructures and UV-transparent electrodes.